Science lesson plan · 8th grade (Year 9 in England) · 45 minutes
Protons, neutrons and electrons
Atoms, elements and the periodic table
CCSS NGSS.MS-PS1-1CCSS NGSS.HS-PS1-1England: KS3 Chemistry: Atoms, elements and compoundsEngland: KS4 Combined Science: Atomic structure and the periodic table
Objective and success criteria
Students will: Protons, neutrons and electrons.
- I can answer questions on today's skill on my own, without help.
- I can explain each step and say why it works.
- I can check my answer and spot a mistake.
Before and after
Needs first: The periodic table: groups and periods
Leads to: Atomic number, mass number and isotopes; How the model of the atom changed over time
Materials: Periodic tables, Atom model kits, Mini whiteboards, A diagram or short video clip of the idea, Printed student sheet (below).
Warm-up · 5 min
- Quick retrieval from earlier learning (The periodic table: groups and periods). Students answer on mini whiteboards.
- Show answers together and note who needs support in the main task.
- Which family does neon belong to? (alkali metals (group 1) / halogens (group 17, also called group 7) / noble gases (group 18, also called group 0)) → noble gases (group 18, also called group 0)Prompt: Is it a soft metal, a coloured reactive non-metal, or an unreactive gas?
- Which family does iodine belong to? (alkali metals (group 1) / halogens (group 17, also called group 7) / noble gases (group 18, also called group 0)) → halogens (group 17, also called group 7)Prompt: Is it a soft metal, a coloured reactive non-metal, or an unreactive gas?
- Which family does lithium belong to? (alkali metals (group 1) / halogens (group 17, also called group 7) / noble gases (group 18, also called group 0)) → alkali metals (group 1)Prompt: Is it a soft metal, a coloured reactive non-metal, or an unreactive gas?
Hook · 5 min
- Show the periodic table and ask what patterns students can see before anything is explained.
- Share the objective: Protons, neutrons and electrons. Read the success criteria together.
I do: model it · 10 min
- Work through the example out loud, saying why you do each step, not just what you do.
- Example: Which particle has a very tiny mass (about 1/1840 of a proton)?
- Step 1: Electrons orbit the nucleus in shells, have a −1 charge and almost no mass.
- Step 2: So the answer is: electron
- Answer: electron
- Pause after each step and ask a student to say what comes next.
We do: guided practice · 10 min
- Do these together. Students try each step on whiteboards before you reveal it.
- Use the hints as prompts rather than giving the answer.
- Which particle has a charge of +1? (proton / neutron / electron) → protonPrompt: Two of the particles are in the nucleus.
- Atomic structure: which statement is true? (The number of protons is called the atomic number. / Electrons are found in the nucleus. / The plum pudding model is today's accepted model of the atom. / Neutrons have a negative charge.) → The number of protons is called the atomic number.Prompt: Where is each particle, and what is its charge?
You do: independent practice · 10 min
- Students work on the student sheet. Circulate and check the first two answers of every student early.
- Students who finish: write a question of their own for a partner, with the answer.
The 8 questions are on the student sheet below, with answers in the key.
Exit ticket · 5 min
- Two questions on their own. Sort answers into got it / nearly / not yet to plan the next lesson.
- Atomic structure: which statement is true? (Protons and electrons have the same mass. / An atom has no overall charge because it has equal numbers of protons and electrons. / Electrons are found in the nucleus. / Neutrons have a negative charge.) → An atom has no overall charge because it has equal numbers of protons and electrons.Prompt: Where is each particle, and what is its charge?
- Which particle has no charge? (proton / neutron / electron) → neutronPrompt: Two of the particles are in the nucleus.
Watch out for
- Everyday meanings of words getting in the way of the science meaning: define key words explicitly.
- Remembering facts without the reason: ask "why?" and "what is the evidence?"
Support and stretch
Support
- Review first: The periodic table: groups and periods.
- Use concrete materials: periodic tables.
- Give the first step of each question, or a partly worked example to finish.
- Pair with a confident partner for the guided practice.
Stretch
- Move on to: Atomic number, mass number and isotopes; How the model of the atom changed over time.
- Explain a common mistake in writing and how to fix it.
- Write a word problem that uses today's skill, then solve a partner's.
Homework and more practice
Free online practice with hints and printable worksheets for this skill: eurekami.com/science/grade-8.
Free lesson plan from eurekami.com/lesson-plan-builder